mxtool: fix command-specific option parsing regression
mxtool: fix command-specific option parsing regression

wdv4758h/ZipPy,wdv4758h/ZipPy,wdv4758h/ZipPy,wdv4758h/ZipPy,wdv4758h/ZipPy,wdv4758h/ZipPy,wdv4758h/ZipPy,wdv4758h/ZipPy